The iron thing under the CPU fan is the CPU heatsink.

Computer heat dissipation is actually the process of heat transfer, the purpose is to bring the heat generated by the CPU to other media, to control the CPU temperature in a stable range. Depending on the environment we live in, the heat from the CPU is ultimately released into the air. And the heat transfer process is the role that heat sink should play. Heat convection is the main way to heat to cool the 500w heat sink.

According to the different means of heat conduction and heat convection, heat sink products can be divided into active and passive ways. Active means that there are energy sources unrelated to the heating element involved in forced cooling, such as fans, pumps in liquid cooling, and compressors in phase-change refrigeration. These cooling methods are generally characterized by high efficiency, but they also require the assistance of other energy sources. Passive, on the other hand, means simply relying on the heat sink or heatsink fin to dissipate by itself.